An innovative approach to fuel burners is illustrated in U.S. Pat. No. 3,425,058, issued Jan. 28, 1969, to Robert S. Babington. The burner therein disclosed represents an adaptation of the liquid atomization principles disclosed in U.S. Pat. Nos. 3,421,699 and 3,421,692, issued Jan. 14, 1969, to the same named inventor and his co-inventors in developing the apparatus and method shown in these patents.
In brief, the principle involved in the aforementioned patents is that of preparing a liquid for spraying by causing it to spread out in a thin film over the exterior surface of a hollow plenum chamber which contains at least one orifice. When gas is introduced into the interior of the plenum, it escapes through the aperture and thereby creates a very uniform spray of small liquid particles.
By varying the number of apertures, the configuration of the apertures, the shape and characteristics of the surface, the velocity and amount of liquid supplied to the surface, and by controlling the gas pressure within the plenum, the quantity and quality of the resultant spray can be optimized to suit the particular burner application.
It is this basic principle, described above, that was utilized in the development of the burner disclosed in said U.S. Pat. No. 3,425,058.
In the above mentioned patent, the burner is so simple that it might even be called a fuel atomizing subsystem for a burner rather than a complete burner. Indeed, from this very simple burner or subassembly evolved the more sophisticated and complete burner described in the present invention. In the earlier said U.S. Pat. No. 3,425,058, the burner is comprised of a simple atomizing chamber having a cover thereover, the cover being provided with a spray discharge port to discharge the atomized fuel in a generally vertical direction. Disposed within the atomizing chamber is a hollow plenum type atomizer that is in communication with an outside source of pressurized air. Liquid is introduced into the atomizing chamber so as to flow over the exterior surface of the atomizing plenum. Exesss fuel that is not sprayed off flows downwardly into a drain where it is recirculated via a pump means to the liquid supply line. The atomizing plenum is provided with a small aperture centrally located beneath the opening in the cover, and the air exiting therefrom creates a fine mist which is discharged upwardly and out of the atomizing chamber for combustion external to the system. Means comprising a series of regulatable apertures are also provided in the atomizing chamber such that aspirated air can be drawn into said chamber or burner and mingled with the spray as it discharges from the opening in the top cover.
From this very simple version of a fuel burner was derived more sophisticated equipment, such as that shown and discussed in an article in the Jan. 1976 issue of Popular Science entitled "Clog-Proof Super Spray Oil Burner". As noted in the article, one development that evolved was the use of two atomizing plenums arranged to discharge the atomized liquids towards each other to create a more stable flame and a good place to initiate ignition.
Other arrangements of opposed spray heads are also suggested in U.S. patents by Babington. namely U.S. Pat. No. 3,751,210 dated Aug. 1973, and U.S. Pat. No. 3,864,326 dated Feb. 1975.
All of the above noted developmental work based on the utilization of the "Babington" principle proved conclusively that the system was perfectly capable of use in a fuel burning system and that, if properly designed, such a system has the potential of evolving into a commerical, practical, highly efficient fuel burner which can be used for domestic heating furnaces.